Doping of semiconductor materials using n-type or p-type dopants is an important step during the manufacturing of transistors. Doping procedures are carefully controlled to produce a desired dopant concentration profile in the semiconducting material. If the doping results in a concentration that is too high, an increase in the leakage current and short channel effect (SCE) may occur. However, if the doping results in a concentration that is too low, the threshold voltage of the transistor may increase beyond an acceptable level.
As technology advances, transistors become smaller and the gate length approach lengths on the order of less than 16 nm. It becomes increasingly difficult to provide adequate doping profiles for such small devices, especially for those transistors that are driven at higher voltages. These high voltage transistors are also commonly known as I/O devices or power transistors since they handle higher voltages than core logic-based transistors.